Sound deadening case means for electric clock



1964 R. SIEF'ERT 3,161,013

SOUND DEADENING CASE MEANS FOR ELECTRIC CLOCK Filed March 26, 1962United States Patent Ofiice 3,161,013 Patented Dec. 15, 1964 3,161,013@OUND DEADENTNG CASE MEANS FOR ELECTRIC CLOCK Roland Siefert,Schwenningen (Neckar), Germany, as-

signor to Kienzle Ulirenfabriken A.G., Schwenningen (l ieckar), Germany,a corporation of Germany Filed Mar. 26, 1%2, Ser. No. 182,521 3 Claims.(Cl. 58-=-41) The present invention relates to battery poweredelectrically wound clocks and more particularly to clockwork supportmountings in works housings.

in this type of clock the inner end of the mainspring is usually fixed,as to a stub shaft on a frame, and the outer end connected to a barrelor disc rotatable or oscillatory about the stub shaft.

Through a pawl on the disc and engaging on a ratchet wheel on the maindrive shaft of the work train, unwinding of the spring drives theratchet wheel and works. The mainspring is wound by a blow, imparted byan armat-ure, to turn the disc in the reverse direction, with the pawlriding freely back along the periphery of the ratchet wheel. Thearmature strikes the disc somewhat tangentially, usually at anelectrical contact lug thereon, when the disc and contact lug turn,during unwinding of the Spring, to a position to engage the armature forcompleting magnetizing circuit for the actuating electromagnet. A smallstorage spring is usually added to the works to keep the clock runningwhile it is being wound. Such wind-up devices are well known, and assuch are not novel features of the invention.

The armatures are usually biased from the associated magnet by gravityor a light spring and function somewhat in the same manner as for asingle stroke bell clapper and are often called clapper armatures.

The inherent disadvantage of clocks having these clapper armatures isthe disturbing noise produced by the blow of the armature on the contactor disc or against the magnet.

Many possibilities for the practical elimination or dampening of thenoise have been explored but the beneficial results heretofore have beenmeager. There have been constructions involving electrical insulationmounts for the battery which resulted in the need for complicatedconductive elements.

In general, the prior construction involved mounting the works directly,or by posts, on the clock dial plate. In the case of expensive clocksthe works were mounted on a housing plate carrying the dial plate. Overthe works was disposed a works capsule or cover which was fastenedeither to the housing plate or the back side of the dial plate, and moreor less sealed at the dial plate or at the housing plate. The winding-upnoise of the clapper armature was readily transmitted to the dial, or tothe housing plate, whereupon either the latter or the dial plate becamea noisy diaphragm.

Moreover, the combination of the capsule and the dial plate or housingplate produced a resonant sound chamher. The noise of the wind-up actionwas very easily heard.

Numerous cures have been sought, for example, the posts for mounting theworks on a mounting member in the housing were supported in ubber orplastic. Any dampening of the conducted noise was not perceptible.Moreover, mounting of the works was no longer exact. Dampening elementson the clapper armature could be employed only in few instances since bytheir use there was an appreciable accompanying loss in efliciency ofthe electro-magnetic system and the battery had to be replaced morefrequently.

No practical solution to the problem was found for eliminating theconducted noise from the outer parts of the clock, that is, from thedial plate or housing.

In the present invention there is no metallic connection between theworks or the wind-up mechanism and the outer part of the clock or theworks case. This is accomplished by use of a plate of soft or slightlyyieldable electrical insulating material mounted fast in a clock case asa rear partition or false cover for the case and to which are mountedthe works and the wind-up mechanism within the case.

In the accompanying drawing:

FIG. 1 is a nearly diametric vertical cross sectional view along theline 1-1 of FIG. 3 looking in the direction of the arrows of said lineand showing one for-m of the invention.

FIG. 2 is a similar view of another form of the invention.

P16. 3 is a rear view of the partition plate and FIG. 4 shows aconstruction detail.

FIG. 1 shows a works case or housing 1 having a forward end-wall 1a anda rearwardly projecting flange 1b therefrom. A dial plate (not shown)may be mounted, for instance, on the end Wall. The works housing isprovided at the rear with a plate 3 of slightly soft electricalinsulation and noise isolating material such as a thermoplastic,methylmethacrylate or polystyrene for example. The plate 3 may besuitably mounted fast on the housing as by posts 5' and passing throughholes 5 secured to the end wall 1a, or it may he, say, force-fitted atthe edge portions 6 of the plate in and against the fiange 1b. The plate3 carries the entire wind-up mechanism consisting of the usualelectromagnet 14 with clapper armature 114, the oscillatory wind-up disc13 with pawl, and the main spring 113. By means of posts 7, preferablythree in number, the clockwork, generally designated 8, is mounted onthe isolating or insulating plate 3. The battery is received in a recessa in the lower part of the back side of the plate 3.

In any suitable manner, as by a close fit, a back cover plate 4 isfastened to the insulating plate 3. The electric connectors 12 and 19from the battery 10 to the electromagnetic wind-up device are on thesame side of the plate 3 with the battery, the connector 12 beingmentioned later as a mounting plate. The battery and the works 8 arecarried on opposite sides of the plate 3 from each other so that nocorrosion of the wind-up device or works can occur due to electrolyteexuding from the battery. This is important in clocks of this type sincerunning of the clock turns the disc in the direction for closing theswitch contacts C between the battery and the magnet. When the batterybecomes too Weak to actuate the clapper armaure, the magnet continuallydraws current from the battery which is likely to cause perforation ofthe zinc container of the battery and permit escape of electrolyte. Theelectrolyte usually gives off ammonical and other fumes injurious toclock works as well as efliorescent salts.

In FIG. 2 there is shown a modified form of the invention. Here no workshousing in the usual sense is employed but only an end wall or worksplate 2. The isolation part 3' has a rear wall 3a similar to the plate 3in FIG. 1 and has a forwardly projecting flange 11 around the wall whichmeets the works plate 2 as at 2a to form a Works case or capsule. TheWorks 8 are not shown but may be mounted on the isolation part 3' as inFIG. 1 by means of three posts and the part is mounted on the worksplate 2 as by posts 5. Here again the part 3 has a recess 9 in the rearwall 33a for the battery.

The isolation part 3' and the isolation plate 3 are preferably of roundiron, i.e., respectively cylindrical and circular and both carry abattery 19 in their lower part. On the side of the wall 3a on which theworks to be wound are situated, there is fastened the electromagneticwind-up device consisting of the magnet, oscillatory disc 13, and thedrive or main spring. The works 8 and the disc are preferably connectedto the positive pole of the battery. For the stabilization of theirpositions, the tines posts and the oscillatory disc may be mounted onthe mentioned stiff metallic mounting plate 12 secured by eyelets 7' onthe isolation plate 3 or the wall 3 with the posts passing through theeyelets.

In FIG. 3 there is shown the stiff metallic plate 12 on the back side ofthe plate 3, to which metallic plate are secured the posts 7 and thestub shaft pin 17 of the oscillatory disc 13. The metallic plate also isprovided with a clip 9' and serves as a battery holder and groundconductor from the battery lit to the disc. The other pole of thebattery is connected to an end of the magnet coil by a lead 19.

in FIG. 4 there are shown details of the rim 6 of the plate 3 forengaging the casing at the flange 1b. The rim 6 includes a forwardannular flange 15 which may be provided with annular serrations 20, ashoulder 21 and a back flange 22 on which to fit the cover i.

The operation can be described more easily by reference to FIG. 3,showing the disc 13 in a position just before the main spring is to bewound. As the contacts C close a winding blow is given to the disc 13 bythe clapper armature 23 to wind the mainspring a partial turn.

There is no metallic connection between the stiff mounting plate 12 andthe case or cover and the noise of the blow is not transmitted to anyappreciable extent to these outer parts.

To close off sound passage in the zone of setting spindle 24 the centralportions of the plate 3 or wall 3a and cover 4 are provided withtelescoping nipples 25 and 26 respectively and through which the spindle24 passes. Packing 28 such as felt between the spindle and the innernipple is employed to reduce sound transmission.

As the spring unwinds, the contacts C on the disc and the clapperarmature 23 respectively approach each other and finally make contact,thereby completing the circuit of the battery and the electromagnet.Upon magnetization of the magnet, the armature is suddenly lifted toknock the disc 13 in a counterclockwise direction and thus wind themainspring to a certain extent.

The invention claimed is:

1. In an electrically wound clock of the type having 8' a mainspringintermittently wound by a periodic blow on a carrier for the springimparted by a clapper armature and cooperating electromagnet, thecombination of a front wall member and a rear wall member, the latterbeing of somewhat soft yieldable material having noise deadening andelectrical insulating properties, one of the members having a completeperipheral flange and extending to the other and joining same to providea works casing; a works train and wind-up mechanism therefor carried onthe rear wall member and between the two members; a rear cover securedto the rear Wall member and free from metallic connection with the frontwall member.

2. In an electrically wound clock having a forwardly facing dial, acasing including a rear case wall of somewhat soft, yieldable sounddeadening electrical insulating material, and a clock works andelectrically operated wind-up means therefor in the casing and mountedonly on said wall at the forward surface thereof to provide a low soundconduction of the noise of the wind-up means to the exterior of thecasing, said wall being provided at the rear face thereof with a recessfor receiving at least part of a battery to actuate the wind-up means,means for holding the battery in the recess, and posts for mounting theclock works, a stub shaft for mounting a part of the wind-up means onthe rear Wall, and a stiff etallic mounting plate on the rear face ofthe rear Wall and remote from the margins of the Wall for maintainingthe works and stub shaft in predetermined position.

3. A clock as claimed in claim 2, said plate being an electricalconductor from the battery to the wind-up means.

References Cited by the Examiner UNITED STATES PATENTS 1,345,766 7/20Hammond 58-53 2,245,918 6/41 Hobbs 58--53 X 2,491,453 12/49 Knobel 58-522,922,276 1/60 Braitsch et al. 58-53 X 3,049,861 8/62 Jensen 58-53FOREIGN PATENTS 727,118 3/32 France.

ROBERT L. EVANS, Primary Examiner.

JOSEPH P. STRIZAK, LEO SMILOW, Examiners.

1. IN AN ELECTRICALLY WOUND CLOCK OF THE TYPE HAVING A MAINSPRINGINTERMITTENTLY WOUND BY A PERIODIC BLOW ON A CARRIER FOR THE SPRINGIMPARTED BY A CLAPPER ARMATURE AND COOPERATING ELECTROMAGNET, THECOMBINATION OF A FRONT WALL MEMBER AND A REAR WALL MEMBER, THE LATTERBEING OF SOMEWHAT SOFT YIELDABLE MATERIAL HAVING NOISE DEADENING ANDELECTRICAL INSULATING PROPERTIES, ONE OF THE MEMBERS HAVING A COMPLETEPERIPHERAL FLANGE AND EXTENDING TO THE OTHER AND JOINING SAME TO PROVIDEA WORKS CASING; A WORKS TRAIN AND WIND-UP MECHANISM THEREFOR CARRIED ONTHE REAR WALL MEMBER AND BETWEEN THE TWO MEMBERS; A REAR COVER SECUREDTO THE REAR WALL MEMBER AND FREE FROM METALLIC CONNECTION WITH THE FRONTWALL MEMBER.